1. Field of the Invention
The present invention relates to a flexure and a head suspension with the flexure to which a head is attached to read and write data on a disk in a hard disk drive.
2. Description of Related Art
A hard disk drive incorporated in an information processing unit such as a computer has a disk rotatable at high speed and a head supported on a head suspension. When the disk rotates at high speed, the head on the head suspension slightly floats from the disk to read or write date on the disk. The head suspension has the flexure to support the head.
The flexure has a metal substrate, an insulating layer formed on the metal substrate, and wirings arranged on the insulating layer. Each wiring includes first and second ends. The first end is connected to the read/write head and the second end is provided with a terminal for external connection. The terminal is connected to a terminal of a circuit board of the hard disk drive, to make a connection between the head and the circuit board through the flexure.
Japanese Unexamined Patent Application Publication No. 2003-31915 discloses a flexure with terminals each being a flying lead type. The flexure has an opening and wirings arranged on the flexure. A part of the wirings passes over the opening to form the terminals of the flying lead type. The terminal of the flying lead type is also referred to as “flying lead terminal”.
Around the flying lead terminals, an insulating layer and a metal substrate of the flexure are removed by the opening. As a result, the flying lead terminals are not supported from their backs and lower strength.
On the other hand, Japanese Unexamined Patent Application Publication No. 2007-287280 (JP2007-287280) discloses a flexure with terminals each being a non-flying lead type. The terminal of the non-flying lead type is also referred to as “pad terminal”.
Generally, a pad terminal is on an insulating layer that is formed on a metal substrate of a flexure. The insulating layer and the metal substrate extend over a back of the pad terminal and the surrounding area of the back to improve strength of the pad terminal.
However, the pad terminal expands relative to a corresponding wiring of the flexure to increase capacitance between the pad terminal and the metal substrate and deteriorate electric characteristic of the flexure.
To cope with this problem, JP2007-287280 forms an opening through the metal substrate on the back of the pad terminal.
However, the flexure of JP2007-287280 involves variation such as a dip of impedance at the time of signal transmission, so that it deteriorates the electric characteristic of the flexure.